NR과 SBR 가황물의 경도와 강성도에 대한 온도의 영향

진현호 ( Hyun Ho Jin ),홍창국 ( Chang Kook Hong ),조동련 ( Dong Lyun Cho ),강신영 ( Shin Young Kaang ) 한국고무학회 2007 엘라스토머 및 콤포지트 Vol.42 No.3

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 International Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR시편의 여러 온도에서 경도변화를 측정하였으며 Young`s modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young`s modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young`s modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다. Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young`s modulus. The hardness and Young`s modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young`s modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young`s modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

Long second toe: its nail and skin changes

( Geun-hwi Park ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Nail can be affected by trauma, infection, and systematic disorders. In particular, the toe nails are exposed to the repeated and cumulative minor traumas, which usually result in thickened, splitted, and discolorated nails. Considering these, it can be inferred that the long second toe can be related to various nail and skin changes by repeated minor traumas such as friction in shoes, but the study or report on this topic hasn’t been done yet. Objectives: The purpose of this study was to introduce various nail and skin changes on long second toe. Methods: We analyzed the kinds of nail/skin changes of 50 patients with long second toe, enrolled at Pusan National University Hospitals (Busan and Yangsan) from 2013 to 2018. Results: There was no significant difference in the incidence of left and right toe and toenail, and 7 (14%) patients presented bilateral distribution. The most common nail change on long second toe was melanonychia (23, 46%), followed by subungual hematoma (15, 30%), onycholysis (2, 4%), subungual hyperkeratosis (2, 4%), onychomadesis (1, 2%), and retronychia (1, 2%). The most common skin change was corn (9, 18%), followed by paronychia (2, 4%). Twenty (20/50, 40%) patients also had other toe or toenail changes. Among them, the most common site was big toe/nail (13, 62%), and the most common change was subungual hematoma (8, 42%). Conclusion: Through this study, the dermatologists can recognize and diagnose the nail and skin changes of long second toe.

개 이자의 Somatostatin 양성세포의 발달에 관한 면역조직화학적 연구

장인엽,윤상필,정윤영,김종중,문정석,한길현,김영택,안계훈,선희매 조선대학교 부설 의학연구소 1998 The Medical Journal of Chosun University Vol.23 No.2

Cells immnunoreactive for somatostatin(SOM) and glucagon(GLU) were investigated in postnatal day 0, 7, 14, 28, 90, 180 and adult canine pancreas using light microscopic immunohistochemistry. Pancreatic SOM-immunoreactive cells were found in pancreatic acini, pancreatic duct, and pancreatic islet gradually. Pancreatic SOM-immunoreactive cells were more located in pancreatic parenchyme than pancreatic islet throughout pancreas by postnatal day 28. But there was change by the postnatal 3 months : pancreatic SOM-immunoreactive cells were more located in pancreatic islet than acini and duct. It is suggested that the number of the SOM-immunoreactive cells may not increase with age apparently. A small number of SOM-immunoreactive cells that showed GLU-immunoreactivity were also observed in canine pancreatic islet. The physiologic consequences of these changes remain to be determined. These results sugegest that SOM in the developing pancreas may relate to the secretion of pancreatic hormones.

아시아 지역 폐렴 구균의 항균제 내성 현황 및 변화 양상 : Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study

정숙인,김나영,손준성,기현균,고관수,서지연,장현하,김연숙,오원섭,백경란,이남용,송재훈,항생제 내성 감시를 위한 아시아 연합 (ANSORP) 대한감염학회 2004 감염과 화학요법 Vol.36 No.1

목적 : 1980년대부터 페니실린을 비롯한 β-lactam 계열과 비 β-lactam 계열 항균제에 대한 폐렴구균의 항생제 내성이 급격하게 증가하여 국내 뿐 아니라 세계적인 문제로 대두되고 있다. ANSORP 에서는 아시아 지역에서 폐렴구균의 항균제 내성과 그 변화 추이, 내성의 기전 및 위험인자를 분석하고자 본 국제 공동 연구를 시행하였다. 재료 및 방법 : 1999년 11월부터 2001년 8월까지 아시아 지역 12개국의 14개 기관에서 폐렴구균 감염증 환자의 임상 검체로 분리된 침습성 폐렴구균을 대상으로 액체배지 미량희석법을 이용하여 16개 항생제의 MIC를 구하였다. 위험인자의 분석을 위하여 폐렴구균 감염증 환자를 대상으로 의무기록지를 조사하였다. Quellung 반응을 통해 혈청형을 결정하였다. 결과 : 총 685균주 중 52.4%가 페니실린에 대하여 비감수성(중등도 내성 22.9%, 내성 29.5%)을 보였고, 그 빈도는 베트남(92.1%), 스리랑카(85.7%), 홍콩(67.9%), 한국(64.5%)의 순이었다. Erythromycin에 대한 비감수성 비율은 베트남(92.1%), 대만(87.7%), 한국(80.6%), 홍콩(76.8%) 등에서 높게 나타났고, 베트남, 대만, 한국, 홍콩 등의 erythromycin의 MIC_(90)이 32㎍/mL를 넘는 고도내성을 보였다. 홍콩, 싱가포르, 대만, 인도에서는 fluoroquinolone에 대한 내성 균주가 출현하였다. 전체 균주 중 다제내성 균주의 비율은 47.7%였다. 혈청형은 19형과 23형이 가장 많았고, 그 외 6형, 14형 등이 있었다. 페니실린 비감수성 감염증의 위험인자로는 5세 미만(OR=1.7; 95%, CI, 1.2-2.4; P=0.002), 기관지폐질환(OR=2.0; 95%, CI, 1.3-3.1; P=0.003), 악성종양(OR=2.3; 95%, CI, 1.2-4.6; P=0.015), 스테로이드의 사용(OR=2.8; 95%, CI, 1.1-7.4; P=0.032)이 확인되었다. 결론 : 침습성 폐렴구균 균주를 대상으로 한 본 연구의 결과 아시아 국가들에서 페니실린, β-lactam 및 macrolide에 대한 폐렴구균의 내성률 및 내성 정도가 급증하고 있음을 확인하였다. Background : Emergence of pneumococcal resistance became a global issue since 1990s. According to the ANSORP studies with clinical isolates and carriage isolates between 1996 and 1999, some Asian countries showed alarmingly high prevalence of resistance to penicillin and other antimicrobial agents. To investigate the changing trends of pneumococcal resistance, ANSORP study group has performed a multinational surveillance study with invasive pneumococcal isolates from Asian countries. Methods : All isolates from various invasive pneumococcal diseases were prospectively collected from 14 centers in 12 countries between November 1999 to August 2001. Broth microdilution tests with 16 antimicrobial agents were performed according to the NCCLS procedures. Serotyping was performed by means of Quelling reaction with use of group-specific antisera. Results : A total of 685 isolates were collected. Overall, 52.4% of invasive isolates from Asian countries were not susceptible to penicillin (intermediate (1), 22.9%, Resistant (R), 29.5%). Vietnam showed the highest prevalence of penicillin non-susceptibility (1 20.6%, R 71.4%) followed by Sri Lanka (1 71.4%, R 14.3%), Hong Kong (1 24.1%, R 76%) and Korea (1 9.7%, R 54.8%). China (I 19.8%, R 23.4%) and Malaysia (1 9.1%, R 29.5%) also showed remarkable increase in penicillin resistance compared with previous ANSORP data, which were less than 10%. Vietnam (92.1%), Taiwan (87.7%), Korea (80.6%), and Hong Kong (76.8%) showed high prevalence of erythromycin resistance. MIG_(90)S for ciprofloxacin were 4 ㎍/mL (Hong Kong) and 2 ㎍/mL (11 Asian countries except Hong Kong), respectively. Conclusion : Compared with previous data from ANSORP studies, antimicrobial resistance among invasive pneumococcal isolates has markedly increased in Vietnam, Sri Lanka, Taiwan, China, and Malaysia. Continuous surveillance of pneumococcal resistance in Asia is strongly warranted.

제 1 소구치·발치가 수반된 Class Ⅰ 전돌 증례의 치료 전후 변화

장영일,이유현 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.5

본 연구는 제 1 소구치 발치로 양호하게 치료된 Class I 전돌 환자의 치료 전 안모 골격 특성과 치료 전후 변화를 조사하여 Class I 전돌 환자의 치료 계획 수립에 이용하고자 하였다. 서울대학교 병원 치과 진료부 교정과에 내원하여 치열궁 길이 부조화의 양이 7.00mm를 넘지 않고 Class I 전돌 환자로 진단되어 상, 하악 제 1 소구치를 발거한 후 동일한 임상가에 의하여 동일 치료 기법으로 양호하게 치료된 환자 35명 (여자 27명, 남자 8명)을 대상으로 치료 전후 측모 두부 방사선 사진을 계측하여 다음과 같은 결과를 얻었다. 1. 치료 전후 골격 형태는 크게 변하지 않았고 치열, 치조골, 연조직에서 치료 후 유의성 있는 변화가 있었다. 2. 치료 전 골격 형태는 SN-GoGn이 36.56°, AB-MP이 66.92°, ODI가 69.17°, APDI가 81.31°, CF 150.52°로서 수직적인 부조화 경향을 보였다. 3. 치료 전 치열 형태는 절치간 각이 113.11°, U1 to FH가 117.78°, L1 to A-Pog이 7.94mm였으며 연조직 측모상 E line에 대하여 상순이 2.88mm, 하순이 5.43mm 돌출되어 있었다. 4. 치료 후 치열 형태는 절치간 각이 14.46° 증가되었으며 연조직 측모상 E line에 대하여 상순이 2.45mm, 하순이 3.2mm 후방이동되었다. (P<0.001) 5. 치료 전 발치 지수 (EI)는 138.71이었고 치료 후 EI는 148.2였다. The purpose of this study was to evaluate the dentofacial characteristics and the post treatment dentofacial changes of those treated by four premolar extractions and to investigate the factors affecting extraction decision. The sample consisted of 35 patients (27 females, and 8 males) with no more than 7.0mm crowding, diagnosed as Class I protrusion. Pre-treatment and post-treatment lateral cephalograms were evaluated. Computerized statistical analysis was carried out using SPSS/PC+ program. The results were as follows. 1. There was no significant change in skeletal pattern after treatment while there was significant change in dentoalveolar and soft tissue pattern. 2. In pre-treatment skeletal pattern, a tendency toward vertical discrepancy was found. 3. In pre-treatment dental pattern, interincisal angle was 113.11°, U1 to FH was 117.78° and L1 to A-Pog was 7.94mm. Pre-treatment upper and lower lip position was 2.88mm and 5.43mm to E line. 4. After treatment, interincisal angle increased 14.46° and upper and lower lip moved back 2.45mm and 3.2mm to E line. (p<0.001) 5. The EI was 138.71 before treatment and 148.2 after treatment.

임플란트의 collar design이 변연골과 연조직에 미치는 영향

유현상,강선녀,정창모,윤미정,허중보,전영찬 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

연구 목적: 임플란트 경부가 잘 설계된 경우 양호한 연조직 반응을 통해 변연골을 보존하는데 도움이 된다. 본 실험에서는 연, 경조직 경계부에 가장 가까이 위치하는 임플란트의 collar design이 변연골 변화와 연조직 반응에 미치는 영향을 동물실험을 통해 알아보고자 하였다. 연구 재료 및 방법: 2마리의 건강한 Beagle dog에 임플란트 collar design만 다른 두 종류의 임플란트(Neobiotech Co. Seoul, Korea)를 식립하였다. Collar에 bevel 을 부여한 군(Bevel 군)과 "S"자 형태를 부여한 군(Bioseal 군)으로 나누어 마리 당 7개, 군당 7개, 총 14개의 임플란트를 무작위로 식립한 후 Healing abutment를 즉시 체결하였다. 디지털 표준구내 방사선사진을 이용해 4주 간격으로 총 12주간 근원심 변연골 변화를 관찰하였고, 12주에 희생하여 조직학적 분석을 통해 협설 변연골 흡수 및 임플란트 주변 연조직 반응을 평가하였다. Mann-Whitney test를 통해 동일한 방사선 사진 촬영 시점에서 근원심 변연골 변화량 및 조직계측치를 군 간 비교하였고, Kruskal-Wallis test를 통해 방사선 사진상 근원심 변연골 변화량이 시간에 따른 차이가 있는지 군 내 분석 한 후 Duncan test를 통해 사후 검증하였다(α=.05). 결과: 방사선학적 분석 결과 각 촬영 시점에서 두 군간 근원심 변연골 변화량의 차이를 보이지 않았다(P>.05). 군 내에서 시간에 따른 근원심 변연골의 흡수량을 분석한 결과 Bevel 군에서는 시간에 따른 차이를 보이지 않았으나 (P>.05), Bioseal 군에서는 시간에 따른 차이를 보였으며, 4주및8주와 비교했을 때 12주에서 변연골의 증가를 보였다(P<.05). 조직학적 분석 결과 협설측 변연골 흡수량에서 두 군간 차이를 보이지 않았으나 (P>.05), Bevel 군에 비해 Bioseal 군에서 더 견고한 결합조직부착을 관찰할 수 있었으며, 생물학적 폭경의 값은 두 집단 간 차이를 보이지 않은 반면에 (P>.05), 접합상피부착은 Bevel 군에서 유의하게 길었고, 결합조직부착은 Bioseal 군에서 더 길게 나타났다(P<.05). 결론: Bevel 군에 비해 Bioseal 군에서 결합조직부착은 길게 형성된 반면에 접합상피부착은 더 짧게 나타났으며, 생물학적 폭경과 초기 변연골 흡수에는 차이가 없음을 알 수 있었다. 연조직 반응의 차이가 실제 기능하중 하에서 변연골 변화에 미치는 영향에 대해서 향후 연구가 필요할 것으로 생각된다. PURPOSE. The purpose of this study was to investigate the effects of implant collar design on marginal bone change and soft tissue response by an animal test. MATERIALS AND METHODS. Two types of Implant (Neobiotech Co. Seoul, Korea) that only differs in collar design were planted on two healthy Beagle dogs. The implants were divided into two groups, the first group with a beveled collar (Bevel Group) and the second group with "S" shaped collar (Bioseal group). Standardized intraoral radiographs were used to investigate the mesio-distal change of the marginal bone. Histological analysis was done to evaluate the bucco-lingual marginal bone resorption and the soft tissue response adjacent to the implant. Mann-Whitney test was done to compare the mesio-distal marginal bone change at equivalent time for taking the radiographs and the tissue measurements between the groups. RESULTS. Radiographic and histological analysis showed that there was no difference in marginal bone change between the two groups (P>.05). Histological analysis showed Bioseal group had more rigid connective tissue attachment than the Bevel group. There was no difference in biological width (P>.05). Bevel group showed significantly longer junctional epithelium attachment and Bioseal group showed longer connective tissue attachment (P<.05). CONCLUSION. For three months there were no differences in marginal bone change between the Bevel group and the Bioseal group. As for the soft tissue adjacent to the implant, Bioseal group showed longer connective tissue attachment while showing shorter junctional epithelium attachment. There were no differences in biologic width.

안구적출에 따른 위둔덕의 Calbindin D-28k과 c-fos의 변화에 관한 연구

김명,김기훈,김주영,하현철,안명수,김장민,조향훈,정명섭,장인엽 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.2

Changes of Calbindin D-28k- and c-fos-immunoreactivities in the superior collicuclus after Eye Enucleation. Objective and methods: Calcium-binding proteins (CBPs) play an important role in the protection, differentiation and reorganization of the central nervous system. The effects of neonatal retinal deafferentation on a CBPs, calbindin D-28k were examined immunohistochemically in the superficial layer of the rat superior colliculus. Also early gene familly c-fos was examined to evaluate the neuronal characteristics in the superior colliculus after monocular enucleation. Results: On the experimental side of superior colliculus, the number of calbindin D-28k-immunoreactive (IR) cells was reduced (77.4% compared to control), but not fibers. Appearance of c-fos-like immunoreactivity was represented much more in the ipsilateral superior colliculus than contralateral side within 24h after eye enucleation. Conclusion: These results suggest that the changes of retinotectal projection may alter the expressional pattern of calbindin D-28k and c-fos expression.

Dangyuja (Citrus grandis Osbeck) Peel Improves Lipid Profiles and Alleviates Hypertension in Rats Fed a High-Fat Diet

Hyun Ju Hong,Ju Youn Jin,Heekyoung Yang,Won Young Kang,Dong Geon Kim,Sunyi Lee,Younghun Choi,Jae Hoon Kim,Chang Hoon Han,Young Jae Lee 한국실험동물학회 2010 Laboratory Animal Research Vol.26 No.4

Obesity is a major public health problem and significant risk factor for many serious diseases including coronary artery disease, cancer, and diabetes. This study was performed to investigate the hypolipidemic effects and anti-hypertensive effect of Dangyuja (Citrus grandis Osbeck) peel, which is bred on Jeju island, in rats fed a high-fat diet. This study was conducted on 4 equal rat groups which were fed as follows; normal diet group (ND), high fat diet group (HFD), high fat diet supplemented with powdered peel of Dangyuja (1%, wt/wt) group (HFD+Dangyuja), and high fat diet treated with sibutramine simultaneously at a dose of 10 ㎎/㎏ group (HFD+Sibutramine). After feeding the high fat diet, body weight gain and relative weight of adipose tissues and liver significantly increased in HFD group, but Dangyuja peel supplementation protected these HFD-induced changes. The levels of serum triglyceride, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and the atherogenic index significantly decreased in the HFD+Dangyuja peel group compared with the HFD group. The systolic blood pressure was significantly increased by feeding the high fat diet, whereas the supplementation of Dangyuja peel effectively prevented the elevation of blood pressure. Therefore, these results suggest that Dangyuja exerts a beneficial effect on obesity by improving lipid metabolism and alleviating obesity-related hypertension.

보조호르몬요법을 받는 여성 유방암 환자의 모발 변화와 치료 실태에 대한 기초 연구

이재경 ( Jae Kyung Lee ),김창현 ( Chang-hyun Kim ),홍동균 ( Dongkyun Hong ),정경은 ( Kyung Eun Jung ),서영준 ( Young-joon Seo ),김창덕 ( Chang-deok Kim ),이진선 ( Jin Sun Lee ),권인선 ( In Sun Kwon ),박상현 ( Sanghyun Park ),이영 대한피부과학회 2021 대한피부과학회지 Vol.59 No.7

Background: Hormone therapy, which includes tamoxifen and aromatase inhibitors, is the most common adjuvant therapy used for breast cancer. However, only a few studies have reported endocrine therapy induced alopecia. Objective: We investigated the effects of long-term adjuvant hormone therapy on hair in patients with breast cancer, in addition to patients’ concerns and current treatment for hair loss. Methods: Patients completed a questionnaire that included information on self-perceived hair changes after each adjuvant therapy session, distress, and current treatment for hair loss. Using a folliscope, we measured hair density and thickness in each patient and in healthy controls. Results: The study included 93 patients with breast cancer (mean age 51.9±9.8 years). The density and hair thickness were 106.36±21.85 hairs/cm2 and 0.07±0.01 mm in the patient group and 147.86±30.67 hairs/cm2 and 0.07±0.01 mm in the control group (n=98, mean age 52.10±8.40 years), respectively. The mean hair density was significantly lower in the patient group than in the control group; however, no statistically significant intergroup difference was observed in hair thickness. Among 76 patients who perceived hair changes after adjuvant therapy, 71.1% (n=54) were distressed with regard to hair changes. However, only 7.8% of the patients, including two who were treated by dermatologists, currently received treatment for hair changes. Conclusion: Dermatologists should be familiar with hair changes in patients with breast cancer and provide appropriate education to encourage patients to consult dermatologists for hair loss and thinning after breast cancer treatment. (Korean J Dermatol 2021;59(7):521∼526)

흉부 X선촬영 기술의 변천에 관한 연구

이창엽,조평곤,김지닐,최소영,김창균,최종학,김정민,김유현 高麗大學校 倂設 保健大學 保健科學硏究所 2002 保健科學論集 Vol.28 No.2

To find elements which enable improving Quality of image of chest radiography, we attempted to make comparison between chest radiography used currently with that of the past, and following conclusion was reached: 1) It could be confirmed that a dependance on chest radiography was declining, because proportion of chest radiography against overall radiography decreased. 2) There was a change of kVp to a high voltage in a chest radiography, and use of high kVp became a generalization 3) Exposure time was reduced and exposure dose was curtailed accordingly. 4) Apparatus was mainly comprised of 3-phase rectifier circuit and inverter type. 5) It could be confirmed that frequency of applying additional filters for high kVp radiography was insufficient. 6) There was almost no difference in the condition of exposure between hospitals using film/screen and hospitals using CR. But when CR is used for radiography, it was increase in exposure dose due to increase in tube current and it will be necessary to have continuous study on exposure dose by an increase use of CR in the future.